A mushroom is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground on soil or on its food source. The standard for the name “mushroom” is the cultivated white button mushroom, Agaricus bisporus, hence the word mushroom is most often applied to those fungi (Basidiomycota, Agaricomycetes) that have a stem (stipe), a cap (pileus), and gills (lamellae, sing. lamella) on the underside of the cap, just as do store-bought white mushrooms.
“Mushroom” describes a variety of gilled fungi, with or without stems, and the term is used even more generally, to describe both the fleshy fruiting bodies of some Ascomycota and the woody or leathery fruiting bodies of some Basidiomycota, depending upon the context of the word.
Forms deviating from the standard morphology usually have more specific names, such as “puffball”, “stinkhorn”, and “morel”, and gilled mushrooms themselves are often called “agarics” in reference to their similarity to Agaricus or their place Agaricales. By extension, the term “mushroom” can also designate the entire fungus when in culture or the thallus (called a mycelium) of species forming the fruiting bodies called mushrooms, or the species itself.
Mushroom kits are generally a cardboard box that has been pre-inoculated to grow mushrooms. Buttons, portabella and shiitake mushrooms are some of the edible varieties that can be ordered in a kit. Usually, all that is required of the grower is to water the container then place in a cool, dark area. Some kits, however, come with a “humidity tent” to keep the mushrooms damp. No matter what type of mushroom kit you order instructions will be included to guide you through growing the delicious edibles.
Kits can be ordered in various sizes, sometimes, with choices like standard size or giant size mushrooms. The kits, after watered and sheltered from light, can produce mushrooms for up to 15 weeks, depending upon the variety. Some mushroom kits can produce five pounds of mushrooms over weeks.
Many mushroom species produce secondary metabolites that can be toxic, mind-altering, antibiotic, antiviral, or bioluminescent. Although there are only a small number of deadly species, several others can cause particularly severe and unpleasant symptoms. Toxicity likely plays a role in protecting the function of the basidiocarp: the mycelium has expended considerable energy and protoplasmic material to develop a structure to efficiently distribute its spores.